Sierra was extradited in 2008, but has continued to participate in the Colombian justice system, implicatingvarious high-level politicians in dealings with the paramilitaries.

As Verdad Abierta details, a recent hearing in a Medellin court laid out charges against Sierra, who is accused of bringing some 1,724 weapons into Colombia between 1998 and 2001, and sending 11 tons of cocaine abroad.

Like Colombia's other illegal armed groups, the AUC financed much of their activity through the drug trade. Often those selling the weapons would be paid directly in cocaine. This was more efficient than organizing two sets of deals, one to ship cocaine abroad and bring back cash, and another to transfer this cash to weapons dealers.

The criminal gangs that have taken over the AUC's criminal networks also use this kind of barter system, asdo guerrilla group the Revolutionary Armed Forces of Colombia (Fuerzas Armadas Revolucionarias de Colombia - FARC).

Most of Sierra's arms trades appear to have been carried out with Honduran criminal groups -- all but one of the cocaine shipments detailed at the hearing ended up in the Central American country. The deals all involve the shipment of cocaine out of Colombia, where it would be exchanged for weapons which were then smuggled back into the country.

As InSight Crime's map of Sierra's alleged drug trading routes shows (see below), the cocaine was generally produced on farms clustered in the south of the Cordoba department and in the region of Bajo Cauca, to the north of the Antioquia department. The AUC's most powerful leaders, including Carlos Castaño, Salvatore Mancuso and Ramiro Vanoy Murillo, all owned properties in this area. The region was the heartland of the AUC, and remains key territory for the drug trafficking groups that inherited its criminal networks.

The cocaine exited the country through classic trafficking routes; ports in the region of Uraba, on the Caribbean coast; Nariño, on the Pacific coast; and La Guajira, on the Caribbean close to Venezuela. These are all areas that have long been fought over by drug traffickers, and are still heavily used today.

Honduras-based criminal groups would have been good trading partners for the AUC. Honduras lies on the way to the world's biggest cocaine market, the United States, and so it makes sense to send cocaine there before it made the journey north to Mexico and the U.S.

Honduras is also sandwiched between countries which, at the time of these deals, had recently come out of prolonged civil wars; Nicaragua in the 1980s, and Guatemala and El Salvador in the 1990s. The end of these Cold War-era conflicts left thousands of surplus military weapons in the region, many from the USSR, often in poorly-guarded military storage facilities.

The deals listed in the indictment against Sierra all involve the shipment of used, Russian-made, AK-47 rifles. The exchange rate for these seems to vary between three and eight kilos of cocaine per rifle. An AK-47rifle cost around $200 in Honduras in the second half of the 1990s, according to World Bank data quoted by the Small Arms Survey 2007, while the wholesale price of a kilo of cocaine in Honduras in 2004 is estimated at almost $5,000. Taken together, this means Sierra's deals would have represented an extremely good deal for the AUC's partners in that country.

If the Honduran traffickers took the cocaine into the U.S., each kilo would have been worth almost $30,000.

It would also make sense for the paramilitaries, who had an abundant supply of the drug but were in constant need of arms, which deteriorate quickly in the semi-tropical regions where much of the fighting took place.

Colombia's guerrillas have also been reported to carry out such deals with Honduran criminal groups. In 2005 police in the Central American country seized more than 200 weapons, which they suspected were due to be traded with the FARC. The authorities estimated that these would have been paid for with some 2,000 kg of cocaine.

Below is InSight Crime's map of the charges against Sierra, showing the alleged route of cocaine trafficked by the AUC.

**Map:

http://insightcrime.org/insight-latest-news/item/1268-honduran-weapons-for-colombian-cocaine-the-paramilitary-trafficking-routes